Slice of persecution (3)
I believe the answer is:
cut
'slice' is the definition.
(synonyms)
'of persecution' is the wordplay.
'of' says the answer is hidden in the clue.
'CUT' can be found hidden inside 'persecution'.
(Other definitions for cut that I've seen before include "Cross" , "Saw" , "Incision; reduce" , "reduced" , "Clip" .)